PubMed Health⌕ Search

Biomedical subjects

C Blair

Publications and source records attributed to C Blair.

At least 55 records · Page 3Linked to original sources
PubMed1988

Somatosensory projections of cerebellar granule cell layer of giant bushbaby, Galago crassicaudatus.

Recent neurophysiological studies of the granule cell (GC) layer in opossums and rats revealed extensive somatosensory projections to the cerebellar hemispheres and caudal vermis. These projections are organized as asomatotopic mosaics that are species-specific. To determine whether similar projections exist in a primate with a relatively small and simple cerebellum, we explored the GC layer of exposed folial crowns of anterior and posterior lobe cerebellar cortex of anesthetized giant galagos using juxtathreshold natural stimulation of mechanoreceptors and in-depth microelectrode micromapping techniques. We found (1) that stimulation of somatosensory mechanoreceptors by gentle touch, deep pressure, muscle stretch and joint movement revealed projections to the GC layer throughout the mediolateral extent of crus II, paramedian lobule, pyramis and rostral uvula (crus I was unresponsive); (2) that mosaic patterns of peripheral sources and submodality of projections were different for each lobule, and (3) that there were intraspecies and individual differences in subfoliation and in details of projections. Except for differences in mosaic pattern and relative size of different projections, these findings are similar to those in opossums and rats. These data suggest that somatosensory inputs to the cerebellum are not only functionally significant, but that they exist widely among mammals.

Animals↗
PubMed1987

The illusion of catch-up growth in premature infants. Use of the growth index and age correction.

Growth data of 61 premature infants who were observed for 29 months were analyzed to determine if there is validity to the concept of catch-up growth. Weight, length, and head circumference were recorded at each visit. For each measurement, a growth index was calculated to facilitate comparison of infants of different ages and sexes. The age of a child at each visit was also corrected for prematurity by subtracting the number of weeks premature from the postnatal chronological age to generate a corrected age. The corrected age was then used to create a corrected growth index for all variables at each visit. Growth data evaluated in the traditional manner (without correction) suggested that catch-up growth occurred. However, growth data for corrected age more closely approximated the growth of full-term children. Graphic impressions were generally substantiated by Hotelling's T2 tests and factorial and one-way repeated-measures analyses of variance with Bonferroni adjustments. The corrected growth data of appropriate-for-gestational-age children approximated normal expected growth, whereas small-for-gestational-age children still demonstrated subnormal growth at 29 months of age, despite correction. In both appropriate-for-gestational-age and small-for-gestational-age children, catch-up growth appears to be a statistical illusion created by charting growth of premature infants using chronological age rather than the more appropriate corrected age. This finding has important implications for the follow-up of premature infants and may affect the diagnostic interpretation of failure to thrive.

Age Factors↗
PubMed1987

Functional identification of the perioral neuromuscular system: a signal flow diagram.

The components of a neuromuscular system are identified, and anatomical and physiological features of the elements are organized into a signal flow diagram. The elements of the perioral neuromuscular system are described in the context of the system flow diagram developed for a generalized neuromuscular system. Important features of commonality and contrast between limb and perioral systems, and areas of needed research are emphasized. Features of contrast include geometry and insertions of muscles, relative influence of inertial loads, and organization of inputs to motoneurons.

Facial Muscles↗
PubMed1986

EMG recording in human lip muscles: can single muscles be isolated?

Electromyography, recording the electrical activity of muscles, is an electrophysiological method that has been used widely in the study of movement performance by human subjects. Borrowing from the tradition of electromyographic studies of limb muscles, investigators interested in speech production have used the method to address many important experimental questions. Unfortunately, data recorded from craniofacial muscles generally have been discussed without reference to problems of interpretation that could arise due to the unique anatomical features of the muscles, particularly the lip muscles. Anatomical data show that the fibers of different muscles of the lips are interdigitated so that fibers with differing spatial orientation typically are found within a small section of lower lip tissue. The anatomical data are consistent with results of physiological studies of the lower lip muscles that have suggested that motor units with different physiological characteristics are found within a single recording site. Together, the anatomical and electrophysiological data suggest that, even with intramuscular electrodes, the probability of recording from a single muscle of the lip in isolation is extremely low. The fact that the activity of more than one muscle is likely to be sampled critically determines the nature of the conclusions that can be drawn from the data.

Electromyography↗
PubMed1986

Interdigitating muscle fibers throughout orbicularis oris inferior: preliminary observations.

Observations of serial sections from two cadaveric specimens of human lower lip are presented. The complex structure of the muscles of the lower lip region includes several fascicles of fibers that are parallel to the vermilion border and other muscle fibers that interdigitate the parallel structures. Two classes of interdigitating muscle fibers are described: The majority originate inferior to the mucosal-gingival border and have a primarily vertical course. The others originate at the hairy epidermis inferior to the vermilion, course diagonally through the horizontal fibers, and insert near the mucosal-vermilion border.

Aged↗
PubMed1985

Behaviour modification in nursing practice and research: a case study.

Using a behaviour modification programme, an attempt was made to teach a 39-year-old dependent patient with a medical diagnosis of schizophrenia to reacquire and maintain self-care behaviours. Dependence in this project was limited to morning care behaviours, i.e. mouth-washing, face-washing, shaving and bathing. Praise and a token economy programme were used to reduce the number of prompts (help and reminders) the patient needed to accomplish the targeted behaviours. Although the treatment programme ran for only 4 weeks because the patient was prematurely transferred to another ward, an evaluation of the programme shows that nursing staff in psychiatric hospitals can facilitate healthy behaviours in schizophrenic patients through behaviour management skills.

Activities of Daily Living↗
PubMed1984

Functional muscle partitioning during voluntary movement: facial muscle activity for speech.

Electromyographic activity was recorded from multiple intramuscular sites in the orbicularis oris muscle for a set of speech and other motor tasks. Because of its geometric heterogeneity and multiple functions, it was hypothesized that this muscle might be partitioned in a task-dependent manner. Comparison of the timing and amplitude of the EMG activity among the multiple recording sites supported this hypothesis. Because some facial motoneurons in primates, including humans, are monosynaptically activated from area 4 of the motor cortex, it is suggested that this task-dependent muscle partitioning may reflect an aspect of cortical organization.

Adult↗